There is known a hybrid drive (DE No 3338548), for a vehicle, having an internal combustion engine (ICE) and an electrical machine installed in a case; the electrical machine has a stator and a rotor, both capable of rotating. An output shaft of the ICE is coupled to one of rotating elements of the electrical machine, and its other rotating element is coupled by means of a mechanic transmission to the vehicle's driving wheels. In this scheme, the electrical machine converts a part of mechanic energy of the ICE into electrical energy, and transmits the other part of mechanic energy of the ICE to a mechanic gear box. Such drive has a disadvantage of having oversized dimensions of the electrical machine, because the electrical machine must transmit the total ICE torque to the driving wheels.
There is known a hybrid power unit (RU No 2264307) for a vehicle. The power unit is mounted in a case, and includes a drive that comprises an electric power storage-source, connected through a control system to several reversible electrical machines; at least one of the machines is installed in the case, and has a stator and a rotor, both capable of rotation. The rotor of this electrical machine can be coupled to a mechanical power storage-source, and the stator can be coupled to one or several driving wheels on which a braking system is installed. Such drive has the same disadvantage: since the electrical machine with two rotating elements must transmit the total ICE torque to the driving wheels, its dimensions are oversized.
There is also known a drive for a hybrid car (U.S. Pat. No. 5,865,263), herein considered as the nearest related art device (herein also called a ‘prototype’), which comprises: an ICE usable as a mechanic energy source; two electrical machines, wherein the first electrical machine is a reversible electrical machine; a storage battery used as an electrical power storage-source; a planetary mechanism (planetary gear); and a central control system. The ICE has an output shaft coupled to a planet carrier of the planetary mechanism. The ‘sun’ gear wheel of the planetary mechanism is coupled to the shaft of the reversible electrical machine, whereas the ring gear wheel of the planetary mechanism, through a number of gear wheels, is coupled to the shaft of the second electrical machine and to a differential of the driving wheels.
The aforesaid drive has a first disadvantage of having an insufficient torque passed to the driving wheels of the vehicle, which is determined only by the ICE torque, the transmission ratio of the planetary mechanism, and a value of torque of the electrical machine coupled to the ring gear wheel.
A second significant disadvantage of the prototype is the low efficiency, determined by energy losses in the electrical machine, coupled only to one of the central gear wheels of the planetary mechanism, which prevents the transmission of torque from the ICE to the vehicle wheels, if this electrical machine is switched off.
A third disadvantage of the prototype is an insufficient drive torque when the ICE it is switched off. In such a case, the vehicle is moved using the first electrical machine, coupled to the ring gear wheel of the planetary mechanism; whereas the second electrical machine, coupled to the sun gear wheel, is switched off, and its shaft freely rotates.